Progress Rail Services' entry into the genset market came by way of a formal announcement with a display at the RSI Rail Technology Exhibition in Chicago on Sept. 21-24, 2008. Not surprisingly, the Caterpillar-owned company's locomotives will use Caterpillar C18 engines for power. They will also be fitted with CAT's ACERT emissions reduction technology. Each genset is rated at 745 horsepower. Progress' three engine genset, model PR22B, will have a total rating of 2,235 hp, while their twin engine model (PR15B?) will be rated at 1,490 hp. Those are the highest horsepower ratings in the industry thus far. The locomotives will be built on refurbished frames, with all new cabs and appliances. Extended range dynamic braking is an available option as well.

The first of Progress' gensets showed up briefly in Georgia in late August and early Sept. 2007. That unit, PRSX 3802, was apparently a test bed of some sort, as the gensets sat very high on the frame, and the unit had a conventional cab. Future arrivals were spotted in March and April 2008 with higher visibility cabs and much lower hoods. Production of the units has been split between Mayfield, KY and Patterson, GA. Progress documentation also mentions a twin engine model, but no units have been produced yet. In addition to the units listed below, a number of frames have been sighted at Mayfield, KY stripped and prepared for conversion.

In addition to their PR22B genset line, Progress has leveraged its relationship with CAT to produce several larger models, including the PR30C six axle, 3,0005 hp model, and the six axle PR43C, a road genset that couples a 3,600 hp CAT C175 with a smaller 700hp CAT C18. So far Progress is testing five of them former in long-term service on UP, and two of the latter on Norfolk Southern.